Portable mast



June 13, 1944. F L MC ONNEL 2,351,275

PORTABLE MAST Filed July 10, 1942 2 Sheets-Sheet l June 13, 1944.MCCONNEL 2,351,275

PORTABLE MAST Filed July 10, 1942 2 Sheets-Sheet 2 Patented June 13,1944 UNITED STATES raTENT OFFICE PORTABLE. MAST Frederick LouisMcConnel, Emporia, Va.

Application July 10, 1942, Serial No. 450,479

2 Claims.

The invention relates to a portable mast.

An object of the present invention is to provide a simple, practica1 andcomparatively inexpensive portable mast, of great strength anddurability, composed of laminated, cylindrical or other shaped sectionsof plywood or other suitable material and characterized by extremelightness in weight.

While the mast of the present invention is especially designed to beutilized for supporting a radio antenna, it will be understood that itis not limited to such use, as it may be advantageously utilized as 'aflagpole, mast of a yacht, small ship or other boat, and for a number ofother purposes.

It is inherent in a portable mast that it must be made of a number ofsections, since it is not practical to transport the mast in its totallength.

'Heretofc-re, various types of sectional and telescoping masts have beenconstructed utilizing metallic tubing of varying designs and materials.Many of these masts, however, are based upon the sections being joinedby a telescoping joint. Such joints require accurate fits and furtherreduce the efiective height of the mast by the amount the sectionsoverlap.

Also, various types of masts have been constructed utilizing woodsections joined by various means, and generally with one mast sectionoverlapping another. Such a. mast has the disadvantage of being eitherweak at the joint, or the diameter or cross section of the mast must beinvantages will be eliminated and which can be conveniently constructedwithout the necessit for accurate fits at the joints. With these andother objects in view, the invention consists in the novel construction,combination and arrangement of parts hereinafter described, illustratedin the accompanying drawings, and pointed out in the claim heretoappended, it being understood that various changes in the form,proportion andminor details of construction within the scope of theclaims may be resorted to without departing from the spirit orsacrificing any of the advantages of the invention.

In the drawings:

Figure 1 is an elevation of a portable mast constructed in accordancewith this invention;

Fig. 2 is an enlarged detail vertical sectional view showing a joint formast sections of the same diameter;

Fig. 3 is a similar view showing a joint for mast sections of differentdiameters;

Fig. 4 is a horizontal sectional View taken substantially on line 4-4 ofFig. 2, and

Fig. 5 is an enlarged detail view of the anchoring means for the guys.

Referring particularly to Figs. 1, 2 and 4 of the accompanying drawings,the portable mast is composed of laminated, cylindrical mast sections 1,of uniform diameter. Each mast section is formed by cutting thin sheetsof wood or veneer and wrapping and gluing the sheets to provide alaminated cylindrical wooden tube.

In order to secure the required strength and elasticity, the individualsheets 2 of veneer are wrapped so that the wood fibers in the adjacentsheets are arranged at right angles to one another in the well knownmanner of manufacture of the flat plywood board. The fibers of theadjacent sheets may be arranged at other angles, such as disposing thewood fibers in the adjacent individual veneer sheets at an angle of 45.Such wrapping and arrangement will increase the strength of thelaminated cylindrical wooden tube.

The mast sections I, which are of the same diameter, are connectedtogether by a joint comprising laminated semi-cylindrical wooden jointsections 3, spacing and shoulder-forming semicylindrical members 4, andsectional metal bands 5 and 6. The semi-cylindrical joint section andthe semi-cylindrical spacing and shoulder-forming members consist ofplywood tubes which are sawed diametrically so as to form twosemicylindrical half sections.

The inner radius of the joint or coupling sections is equal to the outerradius of the mast sections to be coupled or joined together. These halfsections will have approximately one-eighth of an inch planed orotherwise removed from their vertical edges 1 so that when they areplaced around the mast sections to be coupled, they do not quite join orcontact.

The metallic bands 5 and 6, which are preferably located at the centerand at upper and lower ends of the joint or coupling, have the terminals8 and 9 bent outwardly to form ears through which pass connecting orclamping bolts Ill. The bolts are adapted to clamp the couplings firmlyabout the mast.

The spacing and shoulder-forming semi-cylindrical members 4 are locatedat the inner faces of the coupling sections 3, at the central portionsthereof, and their inner and outer faces are of the same diameter as theinner and outer faces of th mast sections which abut against theshoulders formed by the lower and upper edges of the members 4, asclearly illustrated in Fig. 2 of the drawings.

The spacing and shoulder-forming members 4 form a stop within thecoupling, so that when the coupling is placed on a mast section, themembers 4 will center the coupling between the two mast sections to bejoined and will transmit the weight from the upper mast section directlyto the lower mast section, thereby relieving the coupling sections andconnecting bands of the vertical strain incident to the weight of theupper mast section.

Suitable bolts pierce the spacing and shoulderforming members, thecoupling sections, and the sections of the central metal band 5 and donot pass through the mast sections, which are therefore not weakened bythe bolts which secure the said portions of the coupling together. Whilethree metal bands are provided for each coupling in 1 and 2 of thedrawings, the number of the bands may, of course, be varied, and ifdesired, upper and lower clamping bands 6 may be secured to the couplingsections 3 in any suitable manner.

It has been found ample to provide guys l2 for the mast at every secondcoupling, as illustrated, and these guys may be constructed of wire,chains, or any other suitable flexible material or may be composed ofsections linked together to provide for folding the ys.

Any suitable means may be provided for connecting the upper end of theguys with the couplings, and the guys at each coupling are preferablyfour in number and are shown provided at their upper ends with eyes [3which are connected by links M with eye bolts l5, located at the centerof the couplings and piercing the same between the mast sections.

The guys are preferably connected with anchoring member 16 by means of ashort chain ll having its links engaged by suitable shackles 18 providedat the lower ends of the guys. The anchoring member l6 preferablyconsists of a screw formed by spirally winding a piece of metallic rodof the desired length and diameter.

The anchoring member I6 is provided at its upper portion with a straightshank I9 terminating at its upper end in an eye 29 which is linked intothe lower end link of the chain H, but it may be connected with thelower end of the chain or in any other desired manner.

The eye 29 is designed to be of sufficient size to receive a bar adaptedto form a handle to enable the anchor to be easily and rapidly screwedinto the ground. The anchoring screw is capable of being screwed intoevery type of soil including rocky soil, unless such rocks areconsiderably larger than the cross sectional area of the anchor. It hasbeen found by experiment that this corkscrew type of anchor can bereadily installed in soil when the ordinary type of helical screw anchorcannot be used, the advantage of the corkscrew anchor being that it isadapted to adjust itself to the soil, due to its inherent elasticity. Itis adapted to roll small stones out of its way or shift its positionsufficiently to pass large stones, whereas the usual helical type anchoris stopped when it strikes a stone, unless the stone is small enough tobe shattered by force.

If two or more guys are utilized on a mast, and if their length befixed, they must be attached to an anchor which has a fixed distancefrom the base of the mast. It is usual to supply turnbuckles so that thelength of the guys may be ad.- justed to set the mast in a verticalposition and to take up slack or stretch in the guys.

However, when a large stone or boulder happens to lie at the point wherethe anchor should be installed, it may not be discovered until all theother anchors have been installed, and in an extremely rocky terrain, itmay not be possible to find'a location where all four anchor points areclear of such large stones or boulders.

In such a case, it may be desirable to move the anchor either fartheraway or closer to the base of the mast in order to clear a boulder. Thismovement of the anchor may be such that the fixed length of a guy willnot permit the necessary positioning of the anchor to clear such bouldereven though adjusted to the fullest extent of the turnbuckle.

In order to take care of this condition, the chain I7 is fastened to theanchor I6. The chain is provided with sufiicient link openings that thepin of a shackle 18 may pass through any link of the chain. Each guyterminates at its lower end in a shackle l8 so that it may be fastenedin any link of the chain, as determined by the length of the guy and thedistance of the anchor from the base of the mast.

In Fig. 3 of the drawings is illustrated a coupling which is employedwhen the portable mast is composed of mast sections of two or morediameters. In this form of coupling, shoulderforming, semi-cylindrical,plywood members 2| and 22 are employed in addition to the couplingmembers 23.

The shoulder-forming members 2|, which are located at the center of thecoupling, provide shoulders at their upper edges to receive the uppermast section 24 and the shoulder-forming members 22 are located at theupper portion of the coupling and their lower edges form shoulders tofit against the upper end of the lower mast section 25.

The upper and lower mast-sections are spaced apart by theshoulder-forming members; the sections of the inner shoulder-formingmember 2| are secured by the bolts 26 of the coupling to the sections ofthe outer shoulder-forming member 22 and also to the coupling sectionsas the bolts 26 pass through all of these parts as well as through thesections of the central metal band 21.

It will thus be seen that the coupling shown in Fig. 3 is especiallydesigned so that the bottom half of the coupling will fit the mastsection of larger diameter, and the top-half of the coupling will fitthe mast section of smaller diameter. The mast sections do not' haveprotuberances, either interiorly or exteriorly, and when the portablemast is made up of sections of a plurality of diameters, the smallersections may be arranged within the larger sections to reduce the spacerequired for stowage during transportation.

The portable mast is hinged at the lower end to a suitable base 28 andis'adapted to be swung upward to a'vertical position by a boom 29 and tobe lowered by said boom from a vertical position to a horizontalposition. The lower end of the portable mast is preferably stepped intoa socket of a casting 3| or other metallic member which is hinged to thebase 28 by a horizontal pivot or pintle 32.

The boom 29, which is designed to be constructed of plywood sections 33is hinged at its inner end by a horizontal pivot 34 to the socketforming member 30. Suitable abutting shoulders or other means areprovided for limiting the downward movement of the boom with respect tothe mast, while the hinge joint is designed to be constructed to permitthe boom to be swung toward the mast from a position at right angles tothe same for folding the boom against the mast.

The outer end of the boom is preferably provided with an eye 35 for thereception of suitable means for securing the boom to one of the anchors.The base 28 may be anchored in any suitable manner and is designed toconstitute a permanent portion of the mast. The boom is also preferablypermanently hinged to the mast and is foldable against the side of themast.

As one of the purposes for which the portable mast is especiallydesigned is to support a radio,

antenna, and since such antenna must be connected to a transmitter orreceiver by means of an electrical cable, the tubular mast sections willpermit such cable to run through the hollow center of the mast. As themast sections are spaced apart at their adjacent ends, the coupling maybe provided with suitable means for supporting, at different points, acable containing electric wires so that the upper end of the mast willnot be subjected to the weight of the entire cable. Any suitable meansmay be employed for supporting wire-carrying cable at intervals, forinstance, at every second coupling, or as may be required to relieve thetop of the mast from the entire weight of the cable.

The mast can be constructed conveniently without the necessity foraccurate fits at the joints, and by using the coupling without thenecessity of overlapping at the joints. The mast is exceedingly light,the weight of the mast sections themselves being as light as one poundper foot in heights of 50 to 60 feet, and as little as an average of 1.3pounds per foot in heights up to 75 feet. This is the approximate weightof the mast sections exclusive of guys and couplings. Experience hasdemonstrated that it is impossible to construct a portable mast of equalheight and strength without exceeding these weights, if the mast is madeas heretofore constructed.

What is claimed is:

1. A portable mast including a plurality of imperforate, laminated,plywood, tubular sections composed of thin sheets of veneer securedtogether by an adhesive and a coupling connecting the adjacent ends ofthe mast sections and comprising laminated plywood semi-tubular sectionsspaced apart at their longitudinal edges and arranged in overlapping andclamping relation with the ends of the mast sections and spaced apart atopposite sides thereof, spacing and shoulder forming semi-tubularmembers interposed between the ends of the mast sections and consistingof divided plywood tubes, said semi-tubular members being located withinthe clamping sections of the coupling and spaced apart at the spacedlongitudinal edges of the coupling sections, intermediate and end metalclamping bands composed of sections having their terminals located atthe spaced edges of the coupling sections, adjustable fastening devicesconnecting the ends of the clamping band sections and maintaining thecoupling sections in clamping relation with the mast sections, andseparate fastening devices piercing the intermediate band sections andthe spacing and shoulder forming members and located between and spacedfrom the ends of the imperforate mast sections and securing the saidspacing and shoulder forming members and the coupling sections together,the spacing and shoulder forming members being of material axial lengthandthe coupling being adapted to impart flexibility to the mast to permit Whipping and bending of the same without breakage.

2. A portable mast including a plurality of imperforate, laminated,plywood, tubular sections of different diameters composed of thin sheetsof veneer secured together by an adhesive and a coupling connecting theadjacent ends of the mast sections and comprising laminated plywoodsemi-tubular sections spaced apart at their longitudinal edges andarranged in overlapping and clamping relation with the ends of the mastsections and spaced apart at opposite sides thereof, inner and outerspacing and shoulder forming semi-tubular members interposed between theends of the mast sections and consisting of divided plywood tubes, saidsemi-tubular members being located within the clamping sections of thecoupling and spaced apart at the spaced longitudinal edges of thecoupling sections, the inner sectional shoulder forming membercorresponding in diameter to the smaller of two adjacent mast sectionsand having its upper edge forming a shoulder arranged in abuttingrelation with the adjacent end of the smaller tubular mast section andthe outer sectional shoulder forming member surrounding the innershoulder forming member and having its lower edge forming a shoulderseated upon the upper end of the larger mast section, intermediate andend metal clamping bands composed of sections having their terminalslocated at the spaced edges of the coupling sections, adjustablefastening devices connecting the ends of the clamping band sections andmaintaining the coupling sections in clamping relation with the mastsections, and separate fastening devices piercing the intermediate bandsections and the spacing and shoulder forming members and locatedbetween and spaced from the ends of the imperforate mast sections andsecuring the said spacing and shoulder forming members and the couplingsections together, the spacing and shoulder forming members being ofmaterial axial length and the coupling being adapted to impartflexibility to the mast to permit whipping and bending of the samewithout breakage.

FREDERICK LOUIS MCCONNEL.

